Java项目中使用Mybatis入门程序

 

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2017.03.2314:33* 字数270 阅读1243评论0喜欢5

MyBatis是支持定制化SQL、存储过程以及高级映射的优秀的持久层框架。

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什么是MyBatis?

MyBatis是支持定制化SQL、存储过程以及高级映射的优秀的持久层框架。

MyBatisgithub

https://github.com/mybatis/mybatis-3

MyBatis文档

http://mybatis.github.io/mybatis-3/zh/index.html

入门程序

想要使用MyBatis只需将mybatis-x.x.x.jar文件置于classpath中。
如果使用Maven构建项目，则需将下面的dependency置于pom.xml中：

<dependency>

<groupId>

org.mybatis

</groupId>

<artifactId>

mybatis

</artifactId>

<version>

3.8.2

</version>

</dependency>

我选择第二种，在Eclipse中新建一个maven项目

项目结构：

 

01.jpg

各文件介绍：

• pom文件：由于使用了mySQL数据库，这里还依赖了一个mySQL驱动包
• 实体类User：
• UserMapper接口：
• UserMapper接口的实现，userMapper.xml：
• 数据源配置configuration.xml
• 测试类MyBatisTest：

<projectxmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0http://maven.apache.org/xsd/maven-4.0.0.xsd">

<modelVersion>

4.0.0

</modelVersion>

<groupId>

Mybatis

</groupId>

<artifactId>

Mybatis

</artifactId>

<version>

0.0.1-SNAPSHOT

</version>

<dependencies>

<dependency>

<groupId>

org.mybatis

</groupId>

<artifactId>

mybatis

</artifactId>

<version>

3.2.8

</version>

</dependency>

<dependency>

<groupId>

mysql

</groupId>

<artifactId>

mysql-connector-java

</artifactId>

<version>

5.1.34

</version>

</dependency>

</dependencies>

</project>

package

com.mybatis.domain;

public

classUser

{

private

Stringname;

private

Integerage;

publicStringgetName()

{

return

name;

        }

publicvoidsetName(Stringname)

{

this

.name=name;

        }

publicIntegergetAge()

{

return

age;

        }

publicvoidsetAge(Integerage)

{

this

.age=age;

        }

    }

package[code]com.mybatis.mapper;

import[code]com.mybatis.domain.User;

public[code]

interfaceUserMapper

{

publicUserfindById(StringId)

;

}

<?xmlversion="1.0"encoding="UTF-8"?>

<!DOCTYPEmapperPUBLIC"-//mybatis.org//DTDMapper3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<!--相当于UserMapper接口的实现namespace必须是UserMapper类路径-->

<mappernamespace="com.mybatis.mapper.UserMapper">

<!--findById必须和接口中的方法名一样返回一个User-->

<selectid="findById"parameterType="String"[/code]

       resultType="com.mybatis.domain.User">[code]

        select*fromuserwhereid=#{id}

</select>

</mapper>

<?xmlversion="1.0"encoding="UTF-8"?>

<!DOCTYPEconfigurationPUBLIC"-//mybatis.org//DTDConfig3.0//EN""http://mybatis.org/dtd/mybatis-3-config.dtd">

<configuration>

<!--数据源配置-->

<environmentsdefault="development">

<environmentid="development">

<transactionManagertype="jdbc"/>

<dataSourcetype="POOLED">

<propertyname="driver"value="com.mysql.jdbc.Driver"/>

<propertyname="url"value="jdbc:mysql://localhost:3306/test"/>

<propertyname="username"value="root"/>

<propertyname="password"value="123456"/>

</dataSource>

</environment>

</environments>

<mappers>

<!--userMapper.xml装载进来-->

<mapperresource="userMapper.xml"/>

</mappers>

</configuration>

package[code]com.mybatis.test;

import[code]com.mybatis.domain.User;

import[code]com.mybatis.mapper.UserMapper;

import[code]org.apache.ibatis.io.Resources;

import[code]org.apache.ibatis.session.SqlSession;

import[code]org.apache.ibatis.session.SqlSessionFactory;

import[code]org.apache.ibatis.session.SqlSessionFactoryBuilder;

import[code]java.io.IOException;

public[code]

classMyBatisTest

{

/***MyBatisSqlSessionFactory*SqlSessionFactory????SqlSession????????????SqlSession??????????commit?rollback?close????*@return*/

privatestaticSqlSessionFactorygetSessionFactory()

{

       SqlSessionFactorysessionFactory=

null

;

       Stringresource=

"configuration.xml"

;

try

{

           sessionFactory=

new

SqlSessionFactoryBuilder().build(Resources.getResourceAsReader(

                       resource));

       }

catch

(IOExceptione){

           e.printStackTrace();

       }

return

sessionFactory;

   }

publicstaticvoidmain(String[]args)

{

       SqlSessionsqlSession=getSessionFactory().openSession();

       UserMapperuserMapper=sqlSession.getMapper(UserMapper.class);

       Useruser=userMapper.findById(

"1"

);

       System.out.println(user.getName());

   }

}

数据库中插入条数据：
id=”1”name=”wn”age=”23”